sharding-jdbc中SQLExecutionHook的用法

本篇内容主要讲解"sharding-jdbc中SQLExecutionHook的用法"，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习"sharding-jdbc中SQLExecutionHook的用法"吧!

序

本文主要研究一下sharding-jdbc的SQLExecutionHook

SQLExecutionHook

incubator-shardingsphere-4.0.0-RC1/sharding-core/sharding-core-execute/src/main/java/org/apache/shardingsphere/core/execute/hook/SQLExecutionHook.java

public interface SQLExecutionHook {        /**     * Handle when SQL execution started.     *      * @param routeUnit route unit to be executed     * @param dataSourceMetaData data source meta data     * @param isTrunkThread is execution in trunk thread     * @param shardingExecuteDataMap sharding execute data map     */    void start(RouteUnit routeUnit, DataSourceMetaData dataSourceMetaData, boolean isTrunkThread, Map shardingExecuteDataMap);        /**     * Handle when SQL execution finished success.     */    void finishSuccess();        /**     * Handle when SQL execution finished failure.     *     * @param cause failure cause     */    void finishFailure(Exception cause);}

• SQLExecutionHook接口定义了start、finishSuccess、finishFailure方法

SPISQLExecutionHook

incubator-shardingsphere-4.0.0-RC1/sharding-core/sharding-core-execute/src/main/java/org/apache/shardingsphere/core/execute/hook/SPISQLExecutionHook.java

public final class SPISQLExecutionHook implements SQLExecutionHook {        private final Collection sqlExecutionHooks = NewInstanceServiceLoader.newServiceInstances(SQLExecutionHook.class);        static {        NewInstanceServiceLoader.register(SQLExecutionHook.class);    }        @Override    public void start(final RouteUnit routeUnit, final DataSourceMetaData dataSourceMetaData, final boolean isTrunkThread, final Map shardingExecuteDataMap) {        for (SQLExecutionHook each : sqlExecutionHooks) {            each.start(routeUnit, dataSourceMetaData, isTrunkThread, shardingExecuteDataMap);        }    }        @Override    public void finishSuccess() {        for (SQLExecutionHook each : sqlExecutionHooks) {            each.finishSuccess();        }    }        @Override    public void finishFailure(final Exception cause) {        for (SQLExecutionHook each : sqlExecutionHooks) {            each.finishFailure(cause);        }    }}

• SPISQLExecutionHook实现了SQLExecutionHook接口；它使用NewInstanceServiceLoader注册了SQLExecutionHook；sqlExecutionHooks集合由NewInstanceServiceLoader.newServiceInstances创建；start方法遍历sqlExecutionHooks，执行其start方法；finishSuccess方法则遍历sqlExecutionHooks，执行其finishSuccess方法；finishFailure方法则遍历sqlExecutionHooks，执行其finishFailure方法

OpenTracingSQLExecutionHook

incubator-shardingsphere-4.0.0-RC1/sharding-opentracing/src/main/java/org/apache/shardingsphere/opentracing/hook/OpenTracingSQLExecutionHook.java

public final class OpenTracingSQLExecutionHook implements SQLExecutionHook {        private static final String OPERATION_NAME = "/" + ShardingTags.COMPONENT_NAME + "/executeSQL/";        private ActiveSpan activeSpan;        private Span span;        @Override    public void start(final RouteUnit routeUnit, final DataSourceMetaData dataSourceMetaData, final boolean isTrunkThread, final Map shardingExecuteDataMap) {        if (!isTrunkThread) {            activeSpan = ((ActiveSpan.Continuation) shardingExecuteDataMap.get(OpenTracingRootInvokeHook.ACTIVE_SPAN_CONTINUATION)).activate();        }        span = ShardingTracer.get().buildSpan(OPERATION_NAME)                .withTag(Tags.COMPONENT.getKey(), ShardingTags.COMPONENT_NAME)                .withTag(Tags.SPAN_KIND.getKey(), Tags.SPAN_KIND_CLIENT)                .withTag(Tags.PEER_HOSTNAME.getKey(), dataSourceMetaData.getHostName())                .withTag(Tags.PEER_PORT.getKey(), dataSourceMetaData.getPort())                .withTag(Tags.DB_TYPE.getKey(), "sql")                .withTag(Tags.DB_INSTANCE.getKey(), routeUnit.getDataSourceName())                .withTag(Tags.DB_STATEMENT.getKey(), routeUnit.getSqlUnit().getSql())                .withTag(ShardingTags.DB_BIND_VARIABLES.getKey(), toString(routeUnit.getSqlUnit().getParameters())).startManual();            }        private String toString(final List